Apparatus for heating and sterilizing



PATENTED JAN. 26, 1904.

J. S. FORBES. APPARATUS FOR HEATING AND STERILIZING.

APPLICATION FILED FEB. 27. 1903.

N0 MODEL.

Jokws a aw, 5 E6 UNITED STATES Patented January 26, 1904.

PATENT OFFICE.

APPARATUS FOR HEATING AND STERILIZING.

SPECIFICATION forming part of Letters Patent No. 750,757, dated January 26,1904.

Application filed February 27, 1903. Serial No. 145,305. (No model.)

To all whom, it may concern.-

Be it known that I, J OHN S. FoRBEs, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Apparatus for Heating and Sterilizing, of which the following is a specification.

My invention relates to improvements in apparatus for sterilizing liquids, having for its object the provision of a sterilizer designed, primarily, to operate upon and deliver liquid in such manner as to materially increase the efiiciency of apparatus of the kind noted and to provide means by which the operation thereof is automatically regulated both as regards the 0perating-pressure, output of liquid, and the supply of heat for sterilizing said liquid. It is further desired to materially increase the capacity of a sterilizer of a given size, while at the same time so constructing the device that its parts shall be easily accessible for inspection and cleaning, the arrangement of the whole being such as to render practically impossible the passage of liquid therethrough without sterilization. These objects I attain as hereinafter set forth, reference being had to the accompanying drawings, in which- Figure 1 is a sectional elevation, to some extent diagrammatic, illustrating one form of my improved apparatus. Fig. 2 is an elevation, partly in section, showing the detail construction of the float-operated valves of my improved apparatus, the same indicating the position of the floats relatively thereto.

In the drawings, A represents the external casing of my sterilizer, within which is contained the liquid-holding portion A or casing proper of the sterilizer, both of these casings being supported upon a base-casting A It will be seen that said casting is formed with a cavity or recess a, and between the top surface of said casting and an annular casting a is confined a tube-sheet (4 having a series of openings into which are expanded or otherwise suitably held a numberof tubes (0 extending within the casing A. This casing is made with an upper and lower part, which parts are united and operatively held together in the present instance by a chambered casting (6*, having two annular cavities (L5 and (4, there being in the present instance a series of openings in that portion or wall of the casting a separating these two cavities, as well as a second and larger series of openings through the upper wall of the cavity a. There are in the first of these openings a series of upwardlyprojecting tubes (I, open at both ends and each surrounded and inclosed by a larger tube a which enters and is held in the second of said series of openings. These large tubes are closed at their upper ends and communicate with the interior of the cavity ca,from which leads a pipe (4, connected, if desired, to a steam-trap. I preferably form in the bottom of the cavity a aslight depression, (indicated at (4 and into thisI extend one of the interior series of tubes (0 as shown. It will be seen that a top casting A closes the upper portion of the casing A, which extends from the casting (5 outside of the various series of tubes (4 and a being of larger diameter than its lower portion. It will be understood that this casing is designed to contain the liquid to be sterilized or otherwise operated upon, while the space between it and the external casing A may be filled with some heatnon-conducting substance, as asbestos, so that it serves to effectually insulate said interior casing.

Supported in any suitable manner within the upper portion of the casing A and inclosing within it all of the tubes 6& is an annular partition or confining-section B, open at both ends and having removably placed on its top a fluid-guiding section 6, provided with a bottom in which are a series of openings 6, having short downwardly-projecting sections of tubing so placed as to each enter the upper end of one of the tubes 0, The upper ends of said tubes are loosely held in their proper positions by a perforated plate 6*, which is supported from the under side of suitable brackets 6 projecting from the section B, and serves more particularly to properly space the tubes a when the guiding-section 7) is removed-as, for example, when the device is being inspected or cleaned. An annular inwardly-curved piece 6 is fastened to the upper portion of the inner wall of the casing A just above the section b for the purpose of turning inwardly the body of water rising between the section B and the said casing, it being noted that the upper portion of said ring is of less diameter than its lower portion.

C is a supply-pipe through which liquid is delivered to the sterilizer, and there is in this a valve of any of the Well-known forms (indidicated in dotted lines at c) and having projecting from it a spindle 0, the same entering a float-chamber D, which may be supported, if desired, by means of its connections from the casing A. Said supply-pipe C enters the casting a, so as to deliver liquid around the outside of the lower portions of the tubes (0 within the casing A, the distribution of said fluid being facilitated by means of an annular partition 5, which so limits the opening from the casting a to the space within the casing that the liquid flows into the latter from all sides. A clean-out or blow-off valve 0 is pro- Vided in the pipe C.

The connections of the float-chamber D consist of two pipes (Z and d, of which the first enters the upper portion of the casing A at a point above the section b or, in other words, above the highest point attainable by the water-level, while the second enters said casing at a point below the tops -of the tubes a in such position as to always be below the normal water-level. A float d is attached to the valve-spindle c by means of a rod d the valve 0 being so constructed that it will beopened by downward movement of the float:

(Z from the position shown. A pressuregage (F is operatively connected to the upper portion of this float-chamber, while from its bottom part extends a pipe d to a pressureregulator (Z placed to act upon a valve (Z in a pipe 628, through which steam or other heating fluid is supplied to the sterilizer, said pipe being connected in the present instance to the cavity a in the casting a. A connection (Z leads from this pipe 6Z8 into the space surrounding the tubes (6 within the casing A, and this has in it a valve (Z by which the admission of steam to said space may be 0011- trolled. A steaming-out connection d 11 also leads from this pipe (i into the space a, communicating with the interiors of the tubes (4 the passage of steam thereto being governed by a valve 6 An outlet-pipe E,- having a cut-ofi valve (2', (shown in dotted lines,) leads from the cavity a, formed in the base-casting A and has a blow-off or cleaning-out cock 6. A second float-chamber F is provided with a float f, connected by a rod f to the valve-spindle f of the valve 6 for the purpose of governing the flow of liquid through the pipe E, the said chamber being connected by means of a pipe f to the cavity a in the lower part of the casting A and by a pipe f to the upper portion or steam-space of the casing A. This latter pipe enters the casing at a point above the highest water-level, being arranged in the same manner and that for the same reason as set forth in connection with the chamber D.

In operation water, milk, or other liquid to be sterilized is supplied through the pipe C, and after passing through the valve 0 and rising around the tubes a it flows through the pipe (Z into the float-chamber D until it has attained a level within the apparatus necessary to raise the float (Z sufficiently to close the valve 0. Steam or any other desired heating fluid is then admittedthrough the pipe (Z it being understood, however, that before commencing operations the interior of the device may be conveniently and eflectually sterilized by admitting steam through the pipes (Z and 6 The said heat fluid flows into and around the cavity a flowing up through the tubes (0 and through the tubes a to the cavity a, finally passing out through the pipe a. Should any of the heating fluid condense, it would collect in the depression (6 formed in the bottom of the cavity (0 and from time to time would be carried up through the downwardly-extended one of the tubes a by the current of fluid passing into the same, so as to be finally discharged by the pipe a. As soon as the water or liquid to be sterilized surrounds the heated tubes a its temperature is raised until it reaches the point of ebullition. Under ordinary circumstances Water at this temperature frees or tends to free steam from its exposed surface with but relatively very little disturbance of its surface or change of level; but bythe use of the partition-section B, I so restrict the possible surface at which vapor can be freed that this action will only take place between said section and the inner wall of the casing A, it being noted that the body of liquid surrounding the tubes (0 within the section B is not necessarily heated to the boiling-point. Consequently when this external body of water reaches the boilingpoint that portion of it within the upper part of the casing A and outside of the partition B rises bodily and being guided inwardly by the ring 6 flows at a practically continuous rate over the weir formed by the upper edge of and into the guiding-section 6 into the tubes a Such body of liquid has therefore been heated, as required for sterilization, to a temperature at least equal to that of its boilingpoint due to the predetermined temperature, and it now flows through the tubes a into the cavity a, rising in the pipe E until its level is the same as that within said tubes a The level of the raw or unsterilized liquid is kept at a constant level below the tops of the tubes a by means of the float (Z as above noted, and since the particular sterilizer illustrated is air-tight as the heating of water continues the pressure within the top part of the same will rise, thus tending to force the Water out of the tubes (0 and through the pipe E to a reservoir or to distributing-pipes. The float f, controlling the valve f prevents all of the water which has been sterilized from being thus blown or forced out of the apparatus through the pipe E, since when the said water has fallen to a predetermined level in the tubes (4 said float will close the valve 6. When this takes place, the pressure within the casing will continue to rise until finally the regulator (Z will shut off or throttle the valve (Z sufliciently to prevent further inflow of steam to the heating-pipes or to so cut down the said inflow that there will be no further rise in said pressure. As the temperature within the casing falls, and consequently the pressure also, the regulator (Z again opens the valve (Z and permits suflicient steam to flow in to again start the ebullition of the water and its consequent passage over the weir formed by the upper edge of the guiding vessel I) and thence into the tubes a so that the float f will again rise and open the valve 0.

It will be seen that the water within the tubes (0 before it flows out through the pipe E parts with by far the greater portion of its heat to the incoming liquid rising around the said tubes, so that a very perfect heat exchange is effected, and the water that finally passes out is at a temperature but very little higher than that of the inflowing liquid.

While I have described the operation of my improved apparatus as intermittent, it will be understood that when the various elements thereof are properly adjusted the said operation is practically continuous.

By the use of the section B for restricting the freeing-surface of the portion of the liquid being heated I materially increase the capacity of the sterilizer, since though relatively small volumes of the liquid are under treatment at any one time these are very quickly raised to the boiling-point and pass away, so that there is a constant and rapid circulation within the device, which not only insures a relatively large amount of sterilized liquid for a given quantity of steam, but also prevents the deposit of sediment or scale-forming substances in any part of the device.

By employing a pipe (Z to connect the floatchamber D with the main casing at points above the water-level I am enabled to maintain the liquid at the same height in both of said vessels without having a constant circulation of that portion of said liquid in the float-chamber, the advantage of which lies in the fact that the same body of water remains in this chamber and there is no deposit of scale formed.

The inwardly-curved ring 5 prevents the water which is raised upwardly by the vapor within or under it from falling directly back into the space between the section B and the inner wall of the casing, thus insuring its delivery into the compartment or receiving vessel b. Whenever it is desired to clean or inspect the uppr portion of the interior of the casing A, the guiding vessel 6, with its bottom section b, may be easily removed and the perforated sheet, which is normally held to the brackets b by any desired form of catches, may be allowed to drop to the lower portion of said casing A. When the various parts are again assembled, this piece 6* on being raised insures the proper spacing of the upper ends of the tubes a which otherwise would be most troublesome to return to their original relative positions.

If desired, a safety-valve may be placed in connection with the top of the casing A, although under all except abnormal conditions the automatically-acting floats will actuate their respective mechanism to prevent any undue rise of pressure. It will therefore be seen that by the use of my apparatus it is possible to force under pressure a practically constant amount of sterilized fluid to a reservoir or other center of distribution placed in an elevated position, at the same time so constructing the device that the probability of its failure to properly operate is reduced to a minimum.

I claim as my invention 1. The combination in a sterilizer, of a casing, means for maintaining liquid normally below a predetermined level therein means for heating a portion of the liquid and means for carrying away heated liquid rising above the predetermined level, together with means for limiting the steam-freeing surface of said portion of liquid to be treated, substantially as described. 4

2. The combination in a sterilizer, of a casing connected to a source of liquid-supply, a conduit or conduits therein connected to an outlet, means for maintaining the level of liquid in the casing below an opening or openings into said conduit or conduits, means for applying heat to a portion of the liquid in the casing and means for limiting the steam-freeing surface of said heated portion of liquid, substantially as described.

3. Thecombination in a sterilizer, of a liquid-containing casing, means for applying heat to a portion of the liquid in the casing, means for retaining the liquid normally at a predetermined level, means for carrying away liquid rising above said level, and means whereby a portion of the liquid heated is confined within a space having but a relatively small steam-freeing surface, substantially as described.

a. The combination in a sterilizer, of a casing, means for applying heat to a definite volume of water therein, a partition within the casing confining the liquid heated to the highest temperature to a space having a relatively small steam-freeing surface, a conduit or series of conduits for removing liquid from the casing, a source of supply for delivering liquid to the casing, and means for guiding liq- &

uid raised above a predetermined level into said discharge-conduits, substantially as described.

5. The combination of a casing having within it a conduit open at one end and connected at the other end to an outlet, a conduit for supplying liquid to the casing, means for maintaining said liquid normally at a predetermined level in the casing, and means for guiding said liquid into the conduit when it is caused to rise above its normal level, substantially as described.

6. The combination in a sterilizer, of a casing, means for heating liquid, a conduit or conduits connected to an outlet and provided with a liquid-collecting vessel, means for normally maintaining the liquid within the easing at a predetermined level, and a device for guiding liquid into said vessel whenever said liquid rises a predetermined distance above its normal level, substantially as described.

7. The combination in a sterilizer, ofa casing, a conduit or conduits therein connected to an outlet, means for supplying liquid to the casing, a float-chamber containing a float operative upon the supply-conduit, for normally maintaining the liquid within the casing at a predetermined level, with means for connecting the interior of the casing with the floatchamber both above and below the normal fluid-level, substantially as described.

8. The combination of a casing having supply and discharge pipes, means within the easing for conducting fluid rising above a predetermined level to the discharge-pipe, means for heating the casing by fluid, means for maintaining the liquid in the casing normally below a predetermined level and means operated by the pressure Within the casing for governing the supply of heating fluid thereto, substantially as described.

9. The combination of a casing, a casting having two chambers separate from the space within said casing, a source of supply for heated fluid connected to one of said chambers, a series of tubes extending within the casing, and serving to connect said two chambers, with means for supplying fluid to and conducting it from said casing, substantially as described.

10. The combination of a casing, a casting having two chambers of which one is connected to a source of supply for heating fluid, a series of tubes extending from the first chamber, a second series in communication with the first series and connected with the second chamber, an outlet-conduit from the second chamber, means for maintaining the fluid within the casing at a predetermined level, means for supplying fluid to be heated, and means for conducting said liquid from the casing after it has been heated, substantially as described.

11. The combination in a sterilizer, of a casing, having conduits for fluid supplied to and discharged from the same respectively, means operative upon the fluid entering the casing for normally maintaining the top surface of said fluid below a predetermined level, a Weir within the casing having a space on one side of it connected with the liquid-supply system and having the space on its other side connected with the liquid-discharge system, and means operated by variations in the level of the liquid on the discharge side of the weir for regulating the flow of fluid therefrom, substantially as described.

12. The combination in a sterilizer, of a casing having a weir, a supply and a discharge conduit connected respectively to the spaces in communication with the two sides of said weir a device governed by the changes in the level of the fluid on one side of the weir for controlling the supply of said liquid, and means operated by fluid on the other side of the weir controlling the discharge of said fluid from the casing, substantially as described.

13. In a sterilizer, the combination of a casing, a weir within the same, means for heating the fluid on one side of said weir, means for automatically maintaining the level of the fluid to be heated at a level normally below the edge of the weir, and means for automatically preventing the liquid on the other side of the weir from falling below a predetermined IeVeLvsubstantially as described.

14:- The combination in a sterilizer, of a casing having a conduit within it formed to act as a weir, a pipe connected to the interior of the conduit and a second pipe connected to the space surrounding said conduit, with a floatchamber containing a float operated by changes of fluid-level in the space around the conduit, a second float-chamber having a float operated by changes of the levelof the fluid within said conduit, and valves in said two pipes operated respectively by said floats for controlling the two levels of said fluid within the casing, substantially as described.

15. The combination in a sterilizer, having within it a; weir, of two float-chambers each connected with the space above the weir and also with the liquid-filled spaces below said weir, a supply and a delivery pipe connected respectively to liquid-containing spaces on the two sides of the weir, and a valve in each of said pipes having floats within said float-chambars for controlling the flow of liquid through the casing, substantially as described.

16. The combination in a sterilizer, of a cas ing having within it a partition, means for heating liquid within one of the spaces formed by said partition, a weir in the casing, afloatchamber, a float therein having means whereby liquid to be heated is normally maintained below the level of the weir, and a connection between the float-chamber and the casing, said connection being made to that portion in the interior of the casing divided off from the source of heat by the partition, substantially as described.

17 The combination in a sterilizer, of a casing including a casting having Within it chambers of which one is connected to a source of supply for heating fluid, a series of tubes connecting said chamber with another chamber in the said casting, an outlet from said second chamber, and means for collecting liquid condensed in the first chamber and discharging it into the second chamber, substantially as described.

18. In a sterilizer, the combination of a main casing, a casting having chambers of Which one is in connection With a source of supply for heating fluid, a series of openings in the second chamber of said casting having tubes closed at one end and extending into said main casing, a second series of tubes Within the first series extending into openings in the first scribing Witnesses.

JOHN S. FORBES. Witnesses:

WILLIAM E. BRADLEY, Jos. H. KLEIN. 

